A large amount of genomic and proteomic data is available today and it becomes important
to focus on a single class of molecules and combine large amounts of heterogeneous data. The Molecular Class-Specific
Information System (MCSIS) is a relational database-centered system to aid researchers with the collection and
dissemination of data. It is easy to merge different types of data with a relational database, e.g., mutation data
can be put into a multiple sequence alignment. Likewise, in-house databases can be interconnected with a MCSIS database.
Two databases are based on this technology: the GPCRDB
(G protein-coupled receptors) and the NucleaRDB (nuclear hormone receptors)(1).